How can an affidavit from the US Embassy be used to validate a US marriage license for a Non-O visa application in Thailand?

@Robert **********

You are slightly mixed up on how to get a US marriage certificate 'certified'. You're correct the US embassy here won't stamp them (because marriages in the US are controlled by states not the feds)

BUT

You can fill out that blank affidavit stating the marriage between xxx and yyy in state zzz on date is real and valid and the US consulate WILL notarize that.

Using that you can get an in country 90 day Non-O visa issued based on someone married to a foreigner who legally works here for 2000baht.

In Chiang Mai you need a minimum of 21 days left on your current stamp to apply for that in country visa (as it goes under review for 20 days).

SO as long as your spouse entered on a visa exempt or a tourist visa entry and is either on the 30 day extension from that OR a 60 day covid extension AND has 21 days left on her stamp she can apply for that 90 day Non-O inside the country at the immigration ofice.

The way I said to get the blank affidavit notarized from the US consulate has been done by many many hundreds (perhaps thousands) of 'mericanz who married thais in the US.